Evaluate Asthma Control Research Articles

Follow-up of patients with uncontrolled asthma: clinical features of asthma patients according to the level of control achieved (the COAS study).

Our aim was to study the asthma control achieved in patients with uncontrolled asthma who had received appropriate treatment according to the Global Initiative for Asthma (GINA) 2010 (valid at the time the study was designed), and to analyse the factors associated with a lack of asthma control.This was a multicentre study in routine clinical practice performed in patients with uncontrolled asthma according to GINA 2010. At visit 1, we recorded demographics, asthma characteristics and spirometry. We assessed asthma control using GINA 2010 criteria and the Asthma Control Test (ACT). Treatment was optimised according to GINA 2010. At visit 2, 3 months later, we reassessed spirometry, asthma control and factors associated with failure to achieve control.We recruited 1299 patients with uncontrolled asthma (mean age 46.5±17.3 years, 60.7% women, 25.8% obese). The mean percentage of predicted forced expiratory volume in 1 s was 76.4±12.8% and the mean post-bronchodilator increase was 14.9±6.8%. We observed poor agreement between ACT and GINA 2010 when evaluating asthma control (kappa = -0.151). At visit 2, asthma in 71.2% of patients was still not fully controlled. Patients whose asthma remained uncontrolled were older, had a higher body mass index, greater disease severity, longer disease evolution and worse lung function.After treatment optimisation, most patients did not achieve optimal control according to GINA 2010. Risk factors for failure to achieve asthma control were time of disease evolution, severity, age, weight and lung function impairment (excluded in the GINA 2014).

Impact of nasal symptoms on the evaluation of asthma control.

The united airways concept suggests that patients with asthma typically exhibit parallel inflammation in the upper airway. The resulting nasal symptoms should reduce quality of life and substantially affect the evaluation of asthma control among these patients. This study aimed to assess the association of nasal symptoms with the evaluation of asthma control.Fifty-eight patients with asthma and persistent nasal symptoms were prospectively recruited for evaluations of their sinonasal symptoms and asthma control in a cross-sectional study from August 2013 to June 2016. Participants underwent thorough nasal endoscopy, sinus computed tomography, pulmonary function testing, the asthma control test (ACT), and the Sino-Nasal Outcome Test-22 (SNOT-22) questionnaires to evaluate their asthma control and sinonasal symptoms.There was a significant association between ACT and SNOT-22 scores. Among patients with asthma and chronic rhinosinusitis, ACT scores were closely related to the symptoms of cough, post-nasal discharge, dizziness, waking up at night, absence of a good night's sleep, and waking up tired. Among patients with asthma and chronic rhinitis, the forced expiratory volume in 1 second was closely related to the symptoms of needing to blow nose, runny nose, and cough. Patients with emergency clinic visits during the previous 3 months had relatively high SNOT-22 scores, especially for the symptoms of sneezing, runny nose, nasal blockage, cough, and dizziness.Sinonasal symptom severity was closely associated with measured asthma control status among patients with asthma and persistent nasal symptoms. Therefore, upper and lower airway inflammations should be considered and treated simultaneously.

Sputum interleukin-13 as a biomarker for the evaluation of asthma control.

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Monitoring asthma: no matter how?

The ultimate goal of asthma care is to obtain and maintain control, and optimise prognosis for patients [1]. Monitoring and treatment adjustments tailored to patients' needs and wishes are essential to achieve controlled asthma and are therefore a fundamental part of comprehensive asthma management. However, the best strategy for asthma monitoring and its frequency are still unknown [2]. In daily practice, healthcare professionals combine scheduled routine clinical visits, lung function tests, repeated targeted education and questionnaires to evaluate asthma control and/or quality of life. Furthermore, adherence to treatment is strongly associated with asthma control [1, 3]. Although proper treatment of asthma could prevent exacerbations, several studies have suggested that the majority of patients do not have adequate control of their disease [4]. For a large part, this may be explained by suboptimal adherence; in patients with asthma adherence varies between 30 and 70% [5–7]. Monitoring asthma: towards personalised e-Health! <http://ow.ly/tkaq301VVu8>

Asthma control and severe exacerbations in patients with moderate or severe asthma in Jilin Province, China: a multicenter cross-sectional survey.

BackgroundNo systemic evaluation of asthma control in Jilin Province has been reported. Asthma control might provide the basis for asthma management in this region. A multicenter hospital-based cross-sectional study was performed to investigate the asthma control and related factors for severe asthma exacerbations in patients with moderate or severe asthma in Jilin Province, China.MethodsThe study enrolled 1546 patients in five grade one general hospitals from January to December 2013. Asthma medication, patient self-management, asthma control test (ACT) scores and frequency of severe asthma exacerbations during the follow-up (12 months) were collected via a follow-up questionnaire.ResultsIn the study, 889 patients provided a complete follow-up questionnaire. Severe asthma exacerbations occurred in 54.89 % of patients. ACT score ≤15, asthma medication ≤ 3 months, severe asthma, income level lower than average Per Capita Disposable Income (PCDI) and a lower educational level were risk factors of a severe exacerbation.ConclusionsPoor adherence to asthma medication, poor asthma symptom control, lower income, a low educational level might be possible reasons for the high incidence of severe asthma exacerbations and poor asthma control in Jilin Province of China.

A 1-day visit in a severe asthma centre: effect on asthma control, quality of life and healthcare use.

Patients with uncontrolled asthma report ongoing symptoms, poor quality-of-life and extensive healthcare use (HCU) and might benefit from management by a specialised severe asthma team. It is unknown whether a one-time evaluation by asthma experts, without long-term supervision by a specialised team, provides favourable outcomes. We evaluated asthma control (Asthma Control Questionnaire; ACQ), quality-of-life (Asthma-related Quality of Life Questionnaire; AQLQ) and HCU before and 1 year after a 1-day visit programme in a severe asthma centre, including a multidisciplinary assessment resulting in a personalised management plan to be implemented by patients own pulmonologists.40 uncontrolled asthma patients completed questionnaires (ACQ, AQLQ, HCU) at baseline, and 6 and 12 months follow-up.ACQ improved from 2.6 (interquartile range 1.7-3.2) to 1.8 (1.2-3.2) (p=0.003) and AQLQ from 4.8 (4.0-5.2) to 5.3 (4.4-6.0) (p<0.001). We found a reduction in patients with ≥2 exacerbations (95% versus 17%; p<0.001), ≥1 emergency room visit (78% versus 37%; p<0.001) and ≥1 hospitalisation (47% versus 10%; p=0.001).Evaluation of uncontrolled asthma patients in a 1-day visit programme in a severe asthma centre resulted in significant improvements in asthma control, quality-of-life and healthcare use after 1 year. This 1-day visit approach seems beneficial for uncontrolled asthma patients and might reduce their dependence on expensive treatment modalities and long-term management in specialised centres.

Uncontrolled asthma and its risk factors in Chinese children: A cross-sectional observational study

Objective: Asthma afflicts many children in China but information about asthma management among Chinese pediatric asthma patients is limited. This study aims to evaluate asthma control among Chinese pediatric patients and identify risk factors associated with uncontrolled asthma. Methods: A total of 4223 patients with persistent asthma aged 2–16 years from 42 tertiary hospitals across all regions of mainland China except Tibet were surveyed. Asthma Control Test (ACT), Childhood Asthma Control Test (C-ACT) and Global Initiative for Asthma (GINA) criteria were used to assess asthma control for children aged 12–16 years, 4–11 years and 2–3 years, respectively. Uncontrolled asthma was defined as ACT or C-ACT score ≤19 or GINA-defined uncontrolled asthma. Risk factors associated with uncontrolled asthma were identified using multivariate logistic regression models. Results: Asthma was uncontrolled in 19.9% of the subjects. High rates of uncontrolled asthma were found in subjects with treatment non-adherence (44.1%), concomitant allergic rhinitis (AR) (23.3%), disease duration ≥ 1.5 years (22.8%), and first-degree relatives with AR (21.5%). The risk of uncontrolled asthma was much higher in the treatment non-adherence group compared to the complete adherence group (OR = 5.79, p < 0.001). Concomitant AR, disease duration ≥ 1.5 years, and first-degree relatives with AR were also confirmed as risk factors associated with uncontrolled asthma. Conclusions: About 20% of Chinese pediatric asthma patients had uncontrolled asthma. Treatment adherence and AR were the most significant risk factors. Tailored measures aimed at improving treatment adherence and diagnosis and treatment of AR should be adopted to improve the level of asthma control in Chinese children.

Sputum interleukin‐13 as a biomarker for the evaluation of asthma control

Asthma control refers to the extent to which the manifestations of asthma have been reduced or eradicated by treatment. Interleukin-13 (IL-13) has a central role in Th2 response and serves as a possible therapeutic target in uncontrolled asthma. Fraction of exhaled nitric oxide (FeNO) and sputum eosinophils have modest performance in the evaluation of asthma control. To assess the diagnostic performance of sputum IL-13 for the evaluation of asthma control and furthermore to investigate the performance of sputum eosinophils and FeNO. One hundred and seventy patients with asthma were studied. All subjects underwent assessment of asthma control by asthma control test (ACT), lung function tests, FeNO measurement and sputum induction for cell count identification and IL-13 measurement in supernatants. IL-13 (pg/mL) levels in sputum supernatant differed significantly among patients with well-controlled asthma and those with not well-controlled asthma [median IQR 78 (66-102) vs. 213 (180-265), P < 0.001]. Receiver operating characteristic (ROC) analysis showed that, for the whole study population, the diagnostic performance of IL-13 was superior to both sputum eosinophils and FeNO levels [area under the curve (AUC) 0.92, 95% CI 0.87 to 0.95 vs. AUC 0.65, 95% CI 0.58 to 0.72 vs. AUC 0.65, 95% CI 0.55 to 0.72, respectively]. The diagnostic performance of sputum IL-13 was superior to both sputum eosinophils and FeNO levels for the identification of well-controlled asthma. Sputum IL-13 levels could serve as a useful biomarker for asthma control assessment.

Effects of a 12-month multi-faceted mentoring intervention on knowledge, quality, and usage of spirometry in primary care: a before-and-after study.

BackgroundAsthma is among the most common chronic diseases in adults. International guidelines have emphasized the importance of regular spirometry for asthma control evaluation. However, spirometry use in primary care remains low across jurisdictions. We sought to design and evaluate a knowledge translation intervention to address both the poor quality of spirometry and the underuse of spirometry in primary care.MethodsWe designed a 1-year intervention consisting of initial interactive education and hands-on training followed by unstructured peer expert mentoring (through an online portal, email, telephone, videoconference, fax, and/or in-person). We recruited physician and allied health mentees from across primary care sites in Ontario, Canada. We compared spirometry-related knowledge immediately before and after the 1-year intervention period and the quality of spirometry testing and the usage of spirometry in patients with asthma in the year before and the year of the intervention.ResultsSeven of 10 (70 %) invited sites participated, including 25/90 (28 %) invited allied health mentees and 23/68 (34 %) invited physician mentees. We recruited 7 physician mentors and 4 allied health mentors to form 3 mentor-mentee pods. Spirometry knowledge scores increased from 21.4 +/− 3.1 pre- to 27.3 +/− 3.5 (out of 35) (p < 0.01) post-intervention. Spirometry acceptability and repeatability criteria were met by 59/191 (30.9 %) spirometries and 86/193 (44.6 %) spirometries [odds ratio 1.7 (1.0, 3.0)], in the pre-intervention and intervention periods, respectively. Spirometry was ordered in 75/512 (14.6 %) and 129/336 (38.4 %) respiratory visits (p < 0.01), and in 20/3490 (0.6 %) and 36/2649 (1.4 %) non-respiratory visits (p < 0.01), in the pre-intervention and intervention periods, respectively.ConclusionsA mentorship-based intervention involving physicians and allied health team members can enhance knowledge, quality, and actual use of spirometry in real world primary care settings. A future controlled study should assess the impact of this intervention on patient outcomes, its cost-effectiveness, and its sustainability.Electronic supplementary materialThe online version of this article (doi:10.1186/s12890-016-0220-6) contains supplementary material, which is available to authorized users.

The Link between Uncontrolled Asthma and Sensitization to Inhalant Allergens: Evidence from Jeddah, Saudi Arabia

Background: For optimal asthma control, current guidelines recommend the assessment of allergy phenotype. This study investigates the relationship between asthma control and sensitization to inhalant allergens. Methods: A cross-sectional study was conducted over a one year period since January 2011. Asthmatics were sequentially selected from allergy clinic at King Abdulaziz University Hospital in Jeddah. Evaluation of asthma control was based on GINA guideline. Assessment of the sensitization towards inhalant allergens was measured in-vivo by wheal size and number of positive reactions on the standard skin prick test (SPT). SPSS was used to analyse any statistical correlation. Results: A total of 110 asthmatics with a mean age of 34 ± 14 years were included, 63.6% being females. Asthma was predominantly uncontrolled in 68 cases (61.8%), partly controlled in 26 cases (23.6%) and controlled in 16 cases (14.5%). SPT to common inhalant allergens was positive in 76 asthmatics (77.6%); of which 54 (55.1%) were uncontrolled, 13 (13.3%) partly controlled and only 9 (9.2%) were controlled asthmatics. The predominant allergens were Dermatophagoides pteronyssinus in 57 cases (54.8%), Dermatophagoides farinae in 49 cases (47.1%), cat epithelia in 35 cases (33.7%) and cockroach in 23 cases (22.1%). Uncontrolled asthma was correlated significantly with positive SPT (p=0.038). Conclusions: More than half of the uncontrolled asthmatics population is sensitized to indoor inhalant allergens. This clinically favours the assessment of allergic status in any asthmatic, whose symptoms are not controlled. This is one of the early studies exploring the potential link between asthma control and sensitization to inhalant allergens.

Attitudes and knowledge of obesity risks among Male high school students in Al-Madinah, Saudi Arabia.

Evaluation of asthma control among children and adolescents: Cross-sectional study in West Bank, Palestine Maher Khdour, Malek Abu Ghayyadeh, Hussam Alzeerelhouseini, Dua’a Al-Hamed, Lina Khdour

Factors Contributing Towards Poor Asthma Control in Patients on Regular Medication.

In-spite of the availability of effective medications, it is observed that patients with bronchial asthma on treatment are poorly controlled. An objective evaluation of asthma control especially with respect to inflammation and the factors contributing towards poor control is crucial in obtaining relief of symptoms. 1) To measure the asthma control using modified Mini Asthma Quality Of Life Questionnaire (MAQOL) and sputum eosinophil count; 2) To identify the role of factors viz. age, duration of asthma, severity, compliance, technique of inhalation and knowledge of asthma action plan on asthma control. Total 50 asthmatic patients on regular medication were included in the study after obtaining written informed consent. The asthma-control was evaluated based on history, clinical symptoms, need for short-acting bronchodilators, FEVs1 and sputum eosinophil count with the help of modified MAQOL. A global score of <80% was considered as poor control. The proportion of patients under each factor, in poorly-controlled group (PC) was compared with the well-controlled group (WC). The results were analysed using descriptive statistics and unpaired student's t-test. Of the total, 33 (66%) patients were in PC category with a mean global asthma score of 58.46 ± 2.881 vs 85.2 ± 1.19 in the WC group (34%) (p<0.05). The mean age in PC was 41.41 ± 2.413 vs 29.00 ± 2.157(p<0.05) in the WC. The mean duration of asthma was 16.76 ± 2.761 in PC vs 7.882 ± 2.065 years in WC (p<0.05). The severity score was 7.265 ± 0.4434 in PC vs 6.706 ± 0.64 in WC. Eight patients in PC and six in WC were unaware of the treatment plan. One in PC group and three in WC were unaware of technique of inhalation. One in PC group and three in WC were non-compliant. Mean sputum eosinophil count was 7.441 ± 1.081 in PC vs 5.176 ± 1.201 in WC. MAQOL is useful in evaluating asthma-control. Sputum eosinophil count correlates with asthma-control. Duration of asthma, age and severity contributed significantly to the poor control of asthma. There is a need for an objective monitoring in asthma and the treatment strategies need to be modified accordingly.

Asthma Control Assessment in a Pediatric Population: Comparison Between GINA/AEPP Guidelines, Childhood Asthma Control Test (C-ACT), and Physician’s Rating

A Deschildre, I Pin, K El Abd. Allergy. 2014;69(6):784–790 The goal of this study was to evaluate asthma control based on Global Initiative for Asthma (GINA) 2006, National Asthma Education and Prevention Program (NAEPP), Childhood Asthma Control Test (C-ACT), and physician’s assessment (PA). This prospective study included 527 asthmatic children aged 4 to 11 years recruited over an 18-month period at an office visit. Children with a chronic illness in addition to asthma were excluded. Both tertiary pediatric pulmonology …

Asthma severity, not asthma control, is worse in atopic compared with nonatopic adolescents with asthma

BackgroundThe effects of atopic and nonatopic asthma phenotypes on asthma morbidity are unclear. Moreover, asthma morbidity in patients without atopy might be mediated by immunoglobulin E (IgE). ObjectiveTo determine differences in morbidity in patients with asthma with and without atopy in a population of inner-city adolescents with asthma and to assess the impact of total IgE (tIgE) in this population. MethodsData were obtained from 546 inner-city adolescents in the Asthma Control Evaluation study. A positive skin prick test reaction to 14 aeroallergens and specific IgE to 5 aeroallergens determined atopic status. High (≥75th percentile) and low (≤25th percentile) tIgE levels were categorized. Asthma control (Asthma Control Test) and asthma severity (Composite Asthma Severity Index [CASI]) were measured at multiple time points over 1 year. Fractional exhaled nitric oxide (FeNO) and measurements of morbidity also were collected. Multivariable and repeated measures analyses modeled the relation between atopic status and morbidity. ResultsBaseline CASI scores increased 0.90 point (P < .05) and FeNO increased 0.85 natural logarithmic unit (P < .001) in participants with vs without atopy. Repeated measures analyses showed consistent results. Participants without atopy and increased tIgE had FeNO 0.73 natural log unit higher (P < .01) than low tIgE and a nonsignificant increase in CASI. The CASI score and FeNO levels were higher for high than for low tIgE in participants with atopy. ConclusionIn this population, participants with atopic asthma had worse asthma severity and higher FeNO compared with those with nonatopic asthma, but no difference in control. In all participants, higher tIgE indicated worse severity and higher FeNO. In this population, asthma severity and FeNO might be mediated by IgE in the 2 asthma phenotypes.

Does airway hyperresponsiveness monitoring lead to improved asthma control?

The current guidelines recommend an approach to asthma management based on asthma control, rather than asthma severity. Although several specific questionnaires have been developed and control criteria have been established based on clinical guidelines, the evaluation of asthma control is still not optimal. In general, these indicators provide adequate assessment of current control, but they are more limited when estimating future risk. There is much evidence demonstrating the persistence of airway inflammation and airway hyperresponsiveness (AHR) in patients with total control. Therefore, the objective of this review was to analyse the possible role of AHR monitoring as an instrument for assessing asthma control. We will evaluate its capacity as an indicator for future risk, both for estimating the possibility of clinical deterioration and loss of lung function or exacerbations. Furthermore, its relationship with inhaled corticosteroid treatment will be analysed, while emphasizing its capacity for predicting response and adjusting dosage, as well as information about the capability of AHR for monitoring treatment. Last of all, we will discuss the main limitations and emerging opportunities of AHR as an assessment instrument for asthma control.

Validation of a Spanish version of the childhood asthma control test (SC-ACT) for use in Spain

Abstract Objective The Childhood Asthma Control Test (c-ACT) is a validated tool for determining pediatric asthma control. However, it is not validated in Spanish in Spain. We evaluated the psychometric properties of the Spanish version of the Childhood Asthma Control Test (Sc-ACT) for assessing asthma control in children ages 4–11. Methods This national, multicentre, prospective study was conducted in Spain with asthmatic children and their caregivers. Patients were assessed at 3 visits (baseline, 2 weeks, and 4 months). Clinical variables included: symptoms, exacerbations, FEV 1 , asthma classification, PAQLQ and PACQLQ questionnaire scores, and asthma control as perceived by physicians, patients and caregivers. The Sc-ACT feasibility, validity, reliability, and sensitivity to change were assessed. Results A total of 394 children were included; mean (SD) time to complete the Sc-ACT was 5.3 (4.4) min. Sc-ACT score was correlated with asthma control as perceived by physician (−0.52), patient (−0.53), and caregiver (−0.51) and with the PAQLQ (0.56) and PACQLQ (0.55) scores. Sc-ACT was found to be significantly related to intensity and frequency of asthma symptoms. Cronbach alpha coefficient (CCα) was 0.81 and intraclass correlation coefficient (ICC) was ≥0.85 for all of the items. The global effect size of Sc-ACT was 0.55. The cutoff point scores of 21 or higher indicated a good asthma control and their MCID was 4 points. Conclusion The Spanish version of the c-ACT was found to be a reliable and valid questionnaire for evaluating asthma control in Spanish-speaking children ages 4–11 in Spain.

Prevalence of perennial severe allergic asthma in Italy and effectiveness of omalizumab in its management: PROXIMA - an observational, 2 phase, patient reported outcomes study.

BackgroundWe designed the PROXIMA study (Patient-Reported Outcomes and Xolair® In the Management of Asthma) to determine the proportion of patients with severe asthma sensitive to perennial allergens, and to evaluate asthma control and treatment adherence up to 12 months in patients treated with omalizumab in Italian population. In addition, an ancillary study was designed to explore protein biomarkers and characterize them in relation to severe allergic asthma and treatment effects by proteomic approach.MethodsPROXIMA is an observational, multicenter, cross-sectional and prospective cohort study conducted at 25 centers in Italy, in outpatient settings. The study consists of two phases: 1) a cross-sectional phase plans to enroll 600 patients with severe allergic asthma, in step 4 therapy as per GINA guidelines, aged ≥18 years, needing a step up in therapy, and 2) a longitudinal phase on patients who will start omalizumab add-on therapy per clinician’s judgment at baseline visit (approximately 180–240 patients). The primary variable of the cross-sectional phase is the proportion of patients with severe asthma presenting with perennial form of allergy (skin prick test or in vitro test). The primary variable of longitudinal phase is proportion of patients who achieve disease control (assessed by Asthma Control Questionnaire [ACQ]) with omalizumab at 6 months, and maintain it at 12 months. Secondary variables are patient compliance to omalizumab, patient-reported perception of cognitive and emotional impact of the illness, assessed by Brief Illness Perception Questionnaire (Brief IPQ) and the health related quality of life evaluated by the EuroQoL 5D-3 L (EQ-5D-3 L). Safety endpoints will be recorded during the course of the study. Patients participating in the longitudinal phase will be enrolled for ancillary study if they provide additional informed consent. Protein species in complex mixtures will be identified using innovative MudPIT (Multidimensional Protein Identification Technology) method.ConclusionsThe results of this observational study will provide estimate of patient population allergic to perennial allergens in Italy and information on patient-reported outcomes with omalizumab therapy in a real-world setting. The exploratory proteomic analysis on asthma biomarkers could eventually provide new data to identify responder patients to anti IgE therapy.

Modification of Traffic-related Respiratory Response by Asthma Control in a Population of Car Commuters.

Effects of traffic-related exposures on respiratory health are well documented, but little information is available about whether asthma control influences individual susceptibility. We analyzed data from the Atlanta Commuter Exposure study to evaluate modification of associations between rush-hour commuting, in- vehicle air pollution, and selected respiratory health outcomes by asthma control status. Between 2009 and 2011, 39 adults participated in Atlanta Commuter Exposure, and each conducted two scripted rush-hour highway commutes. In-vehicle particulate components were measured during all commutes. Among adults with asthma, we evaluated asthma control by questionnaire and spirometry. Exhaled nitric oxide, forced expiratory volume in 1 second (FEV1), and other metrics of respiratory health were measured precommute and 0, 1, 2, and 3 hours postcommute. We used mixed effects linear regression to evaluate associations between commute-related exposures and postcommute changes in metrics of respiratory health by level of asthma control. We observed increased exhaled nitric oxide across all levels of asthma control compared with precommute measurements, with largest postcommute increases observed among participants with below-median asthma control (2 hours postcommute: 14.6% [95% confidence interval {CI} = 5.7, 24.2]; 3 hours postcommute: 19.5% [95% CI = 7.8, 32.5]). No associations between in-vehicle pollutants and percent of predicted FEV1 were observed, although higher PM2.5 was associated with lower FEV1 % predicted among participants with below-median asthma control (3 hours postcommute: -7.2 [95% CI = -11.8, -2.7]). Level of asthma control may influence respiratory response to in-vehicle exposures experienced during rush-hour commuting.

Sputum interleukin (IL)‐13 as a biomarker for the evaluation of asthma control

Method We recruited 170 patients (47 with SRA) from two University asthma clinics. Patients were submitted to pulmonary function testing, measurement of fractional exhaled nitric oxide (FeNO), and sputum induction with calculation of inflammatory cells and measurement of IL-13 in the supernatant. Asthma control test (ACT) was used for evaluation of asthma control (ACT values >19 identified well-controlled asthma). Severe refractory asthma was defined by the ATS criteria.

Seasonal risk factors for asthma exacerbations among inner-city children

Asthma exacerbations remain common, even in children and adolescents, despite optimal medical management. Identification of host risk factors for exacerbations is incomplete, particularly for seasonal episodes. We sought to define host risk factors for asthma exacerbations unique to their season of occurrence. This is a retrospective analysis of patients aged 6 to 20years who comprised the control groups of the Asthma Control Evaluation study and the Inner City Anti-IgE Therapy for Asthma study. Univariate and multivariate models were constructed to determine whether patients' demographic and historical factors, allergic sensitization, fraction of exhaled nitric oxide values, spirometric measurements, asthma control, and treatment requirements were associated with seasonal exacerbations. The analysis included 400 patients (54.5% male; 59.0% African American; median age, 13 years). Exacerbations occurred in 37.5% of participants over the periods of observation and were most common in the fall (28.8% of participants). In univariate analysis impaired pulmonary function was significantly associated with greater odds of exacerbations for all seasons, as was an exacerbation in the previous season for all seasons except spring. In multivariate analysis exacerbation in the previous season was the strongest predictor in fall and winter, whereas a higher requirement for inhaled corticosteroids was the strongest predictor in spring and summer. The multivariate models had the best predictive power for fall exacerbations (30.5% variance attributed). Among a large cohort of inner-city children with asthma, patients' risk factors for exacerbation vary by season. Thus information on individual patients might be beneficial in strategies to prevent these seasonal events.